BACKGROUND: Acute kidney failure in children is a catastrophic, life-threatening event. OBJECTIVE: To compare and contrast 2 decades of data, analyzing the underlying causes, associated multiple organ system failures, outcome of dialysis procedures, and other variables of interest. DESIGN: Retrospective examination of clinical data collected between January 1, 1979, and December 31, 1998. SETTING: Regional health care center in the mid-Atlantic area. PARTICIPANTS: Two hundred twenty-eight patients, aged from 1 day to 18 years, had acute kidney failure and were referred to a pediatric nephrology service. MAIN OUTCOME MEASURES: Characteristics, percentage of mortality, intensive care unit admission, procedures, and other variables and causes of acute renal failure. RESULTS: The total number of cases analyzed represented 7% of all patients presented to the pediatric nephrology service. Sex distribution, ethnicity, and survival statistics were unchanged between both decades. The overall survival rate was 73%. One hundred fifty-four patients (68%) were admitted to the pediatric intensive care unit. The following 106 acute extracorporeal procedures were performed on 93 patients (41%): 12 patients received extracorporeal membrane oxygenation, 52 patients underwent peritoneal dialysis, 32 underwent hemodialysis, 3 patients received continuous venovenous hemofiltration, and 7 patients received continuous arteriovenous hemofiltration. Sepsis and burns, other leading causes of acute renal failure in the first decade, are replaced in the second decade by hematologic-oncologic complications and pulmonary failure. CONCLUSIONS: Acute kidney failure following repair of cardiac lesions remains unchanged as a leading risk factor of mortality in both decades. Three organ system failures were associated with more than a 50% mortality rate. Predialysis low serum albumin concentrations emerged as a significant copredictor of mortality.